Thanks Jay!
Talked with my mechanic and he advised me to return the generic short shifter. Personally he thinks a good driver can shift fast enough with a normal shifter and the risk of mis-shifting and ruining the gearbox with the short shifter doesn't compensate.
He told me the short shifter would fit, and since he fitted the Sachs reinforced clutch he must know what's my gearbox like.
I'm going to order the OEM "short" shifter from the GTI Ed. 30/R32 (8J0711046E) and the metal side to side bracket part from the Leon (1J0711202J) and whashers (1J0711067L). Adding the 42 DD bushes should do be enough.
Also, today ordered from deAutoKey a complete interior LED kit. It's my first buy from the USA. Their LED keep the dimming effect that I like in the interior lighting.